Dogs purchased from pet stores more likely to have behavioral problems than animals obtained from small, non-commercial breeders, study says

KANAB, Utah — Dogs purchased from pet stores are more likely to have a range of behavior problems than those purchased from small, non-commercial breeders, says a new study released today from researchers at Best Friends Animal Society and the University of Pennsylvania School of Veterinary Medicine.

The study, conducted by a team of researchers led by Dr. Frank McMillan of Best Friends Animal Society, in collaboration with Drs. James Serpell and Deborah Duffy at the University of Pennsylvania School of Veterinary Medicine, is published in the current issue of the Journal of the American Veterinary Medical Association. The data support what many animal welfare experts have suspected for years regarding animals sold in pet stores. Most pet store puppies are sourced from high volume commercial breeding operations commonly referred to as puppy mills.

The research compares a wide array of psychological and behavioral characteristics of 413 dogs purchased from pet stores with the same characteristics of 5,657 dogs obtained from small-scale, private breeders.

Results show that dogs obtained as puppies from pet stores showed significantly more aggression toward human family members, unfamiliar people and other dogs. For example, dogs purchased from pet stores were almost twice as likely to exhibit aggression directed toward unfamiliar dogs than dogs purchased from small non-commercial breeders. They also a displayed greater fear of other dogs and typical events in pet dogs’ lives, had more behavior problems when left alone at home, and experienced more problems with house-soiling. Such behaviors in young adult dogs are reasons typically cited by people who surrender their pets to municipal animal shelters.

“We’ve long suspected that puppies coming from pet stores have a much higher number of behavior problems, but this investigation—the first large-scale study to specifically look at behavior problems in adult dogs bought as puppies from pet stores—offers strong scientific evidence to confirm those suspicions,” said Dr. McMillan.

“The results were so one-sided that in the wide range of behavior problems we included in our analysis, pet store dogs failed in every single case to even obtain one more favorable score than the comparison group of dogs.”

McMillan and the Best Friends-led research team note that the study did not determine the exact causes for each of the abnormally increased behavior problems in pet store dogs. It is widely accepted that a very high percentage (more than 90 percent) of puppies in pet stores are acquired from puppy mills.

A similar study Best Friends Animal Society’s McMillan, published in 2011 in collaboration with the University of Pennsylvania School of Veterinary Medicine, documented the psychological harm suffered by the breeding dogs in puppy mills.

“It is highly likely that this severe stress plays a prominent role in the increased behavior problems that have now been documented in the puppies coming out of these breeding facilities,” McMillan said.

The researchers do not recommend purchasing dogs from pet stores until the causes of the elevated number and severity of behavior problems in those animals can be identified and solved.

For an interview with Dr. Frank McMillan of Best Friends Animal Society: Please contact Barbara Williamson at 435-644-4408 or barbara@bestfriends.org.

For a copy of the study: Reporters should send an email to dfagen@avma.org and put the phrase “McMillan Article” in the subject line. A copy will be emailed back to you in short order.

About the Study:

The study was conducted by a team of researchers led by Dr. Frank McMillan of Best Friends Animal Society in collaboration with Drs. James Serpell and Deborah Duffy at the University of Pennsylvania School of Veterinary Medicine, and Dr. Elmabrok Masaoud and Dr. Ian Dohoo at the University of Prince Edward Island’s Atlantic Veterinary College.

Breeder-obtained dogs were selected as the group for comparison to pet store-obtained dogs. Study questionnaire included 100 questions, which ask respondents to indicate their dogs’ typical responses to a variety of everyday situations during the recent past. The scales rate the behavior by intensity or frequency.

About Best Friends Animal Society®

Best Friends Animal Society is a national animal welfare organization building no-kill programs and partnerships that will bring about a day when there are No More Homeless Pets® . The society's leading initiatives in animal care and community programs are coordinated from its Kanab, Utah headquarters, the country's largest no-kill sanctuary. This work is made possible by the personal and financial support of a grassroots network of supporters and community partners across the nation.